Eh...I guess. My problem with most of them is they look like backdated Defiants rather than something that was designed from scratch that could evolve into the Defiant - follow?
Not sure what the difference is... the ship is fairly unique and to make it TOS-like there still will be features that say, "Defiant", IMHO.
FWIW, this is how I'd do a TOS Defiant:
I think what gets to me about them all is that it doesn't allow for any kind of true evolution of the ship's history. It's like they nailed down the configuration from the beginning and just refined the technology over the years. I'd rather see something that looks conceptually like a TOS Defiant but not so literal to the DS9 version with the small details like the nacelle shrouds, rear profile, the greeblies on top/bottom.
Ian Keldon's seemed like a true TOS Defiant - someone got an idea for a new ship configuration and whipped up a prototype using available ship components. Over the years, as the design was put thru its paces and refined, it eventually evolved into the DS9 Defiant.
Look at it from an existing example - compare the TOS E to the E-D. Yes, they both have a saucer, a dorsal, a secondary, and two nacelles on pylons but the ships don't look like they just kept swapping out parts over the years until one turned into the other. They're both unique builds.